The man who was captured on camera yelling nasty things to Bristol Palin about mom Sarah Palin while she took a mechanical-bull ride at a West Hollywood bar last September has now sued the political scion in federal court, according to court documents obtained by E! News.

Hanks claims that Palin defamed him by suggesting in an interview that he was the reason she moved back to Alaska, and he objects to his image being used in promos for the upcoming Lifetime series, Bristol Palin: Life's a Tripp.

A source close to Bristol confirmed to E! News that the single mom has been sued and will move to get the lawsuit thrown out. Bristol's camp is convinced Hanks planned all along to heckle the 21-year-old to get attention, the source said, noting that Hollywood TV shares a parking lot with Saddle Ranch, the bar where it all went down.

"Instead, she confronted him," and he's mad about how he came off in the video, the source added.

As for Hanks being angry that he has shown up in Life's a Tripp promos (Lifetime's cameras were following Bristol at the time, as well), his attorney exclusively told E! News that no one ever asked Hanks to sign a release.

Lawyer Michael Gulden said that his client was unaware that anyone was filming them until Bristol left Saddle Ranch with cameras in tow, and was later told by management that her crew had permission for limited filming of Bristol and her friends.

Hanks spoke to Lifetime parent A&E about the allegedly unlawful use of his image, Gulden said, adding that the network was ultimately unresponsive and they had no other choice but to file suit.

A patron of the bar who yelled to Bristol, "You're mother's a whore!" while she rode the bull.

"He was with friends when he observed that Bristol was on the mechanical bull," Gulden told us. "And several of the bar patrons began to talk about their general dislike of the politics of the Palins."

After falling off the bull, Bristol approached Hanks and asked him, on camera, if he was "a homosexual" after he informed her that he wanted her mother to go to hell.

Hanks asked Bristol why she assumed he was homosexual, and she replied, "Because I can tell you are." And, gesturing to a male companion, "That's a nice wife you've got there."

After their run-in, Hanks issued an apology through his lawyer, in which he said he shouldn't have taken out his feelings about Sarah Palin on the former Alaska governor's daughter.

"I wish Bristol success with her television show, and much happiness in the future," he said at the time.

UPDATE: The West Hollywood bar patron who sued Palin for defamation and right to privacy when she taped him criticizing her mother's politics and called him gay, dropped his federal lawsuit against her. But Stephen Hanks immediately filed the case again in state court.

Hanks' attorney, who filed a notice of dismissal of the suit, said this change was merely procedural. "We wanted to add the CEO and the production company," Michael Gulden told E! News.

UPDATE: Hanks dropped his defamation claim against Bristol, but the complaint was dismissed without prejudice, meaning he can refile if he so chooses, according to paperwork filed Sept. 5. He is pursuing his lawsuit against Lifetime.